Field of the Invention
This invention relates to the field of polymer applications for the treatment of wounds.
Background
Around the turn of the new millennium, commercially available hemostatic technologies abruptly changed from ancient to new-age. While cotton gauze had served as the gold standard for treatment of bad bleeds for thousands of years, it was displaced by an arsenal of new materials which had been engineered to rapidly stop bleeding from severe injuries of the extremities. Such technologies were useful to US soldiers in both Operation Iraqi Freedom and Operation Enduring Freedom. The key products contracted to the military include 1) Quikclot® (a registered trademark of Z-MEDICA, LLC) Combat Gauze, a gauze impregnated with kaolin nanoparticle powder which absorbs large amounts of water and hence concentrates clotting factors, 2) the Hemcon Patch® (a registered trademark of HemCon Medical Technologies, Inc.), a freeze-dried bandage composed of chitosan, a material extracted from shrimp shells, and 3) Woundstat® (a registered trademark of TraumaCure, Inc.), a clay mineral-based powder which, like Quikclot, absorbs high volumes of fluid quickly.
Although these products typically have done an adequate job of treating bleeding from extremities or superficial wounds in combat, they all have significant drawbacks. For example, Quikclot nanoparticles and Woundstat granules are very difficult to remove once an injured soldier arrives at a medical facility; this can cause permanent tissue scarring and/or peripheral clotting. Furthermore, these powders also pose a liability of blowing into the eyes of soldiers and medics in the field. The Hemcon Bandage is relatively easy to remove, but it offers little flexibility in application due to the preformed shape of the solid bandage. Combat Gauze, and other gauze types, requires significant manual packing and compression times which put the lives of field medics at significant risk, particularly when under fire. Indeed, the salient common denominator among all currently available hemostats is the requirement for sustained compression. It is also worth noting that even with sustained compression on the bleeding site, such products demonstrate only mediocre effectiveness in treating severe life-threatening bleeds on the battlefield.
Like the solid, compressible products (gauze, bandage, powder) described above, countless other related technologies have also been developed over the last decade using essentially the same form factors and raw materials, with only incremental (or ambiguous) improvements demonstrated in pre-clinical studies. As such, a need exists for a hemostatic material which is easily packable and requires no sustained compression time. Of course, this material also should be highly effective, safe, low cost, durable and easily removable for it to be useful to military and civilian emergency medics.